Adjusting device for spring-loaded key levers



June 16, 1959 w. STUIBER 2,890,782

ADJUSTING nsvxcs FOR spams-1.0mm KEY LEVERS sued Oct. 9. 1956 INVENTOR.

United States Patent D ADJUSTING DEVICE FOR SPRING-LOADED KEY LEVERSWalter Stuiber, Stein, near Nurnberg, Germany, assignor to Triumph WerkeNumberg A.G., Numberg, Germany Application October 9, 1956, Serial No.614,959

Claims priority, application Germany October 13, 1955 20 Claims. (Cl.197-33) The present invention relates to an adjusting device for springloaded key levers, and more particularly to an adjustment device for thespring loaded key levers of an ofiice machine in which the types areactuated by key levers.

Typewriters, accounting machines, desk calculators, and other officemachines include keyboards whose keys are mounted on spring loaded keylevers so that it is necessary to overcome a spring force when the keysare actuated. It is known to provide adjusting means for adjusting thespring force acting on the spring loaded key levers. The adjustingdevices according to the known art vary the tension of the loadingsprings. In the event that all springs acting on a set of key levers aresimultaneously adjusted, considerable forces are required foradjustment, and. a force of 7-8 kilograms may be required for adjustingthe springs of the key levers of a standard typewriter. Consequently,the adjusting devices according to the known art require a transmissionfor adjusting a set of springs associated with a set of key levers.

It is one object of the present invention to overcome this disadvantageof the devices according to the known art, and to provide an adjustingdevice for spring loaded .key levers permitting adjustment of the springforce acting on the key levers without requiring any substantialadjusting force.

It is another object of the present invention to provide :an adjustingdevice for spring loaded levers which does not vary the spring tensionof the respective springs, while producing a variation of the springforce acting on the levers.

It is another object of the present invention to provide an adjustingdevice for spring loaded levers in which a component of the springtension is used for loading the .key levers.

It is a further object of the present invention to vary athe springforce acting on the key levers by varying the .angle between the springand the respective key lever.

It is a further object of the present invention to simulta- :neouslyadjust the spring forces acting on a set of key .levers by moving anassociated set of springs about a common axis between a plurality ofangularly displaced gpositions.

Another object of the present invention is to simulta- :neously adjustthe spring forces acting on a set of key levers without varying thespring tensions of the respective :springs so that only frictionalforces have to be overcome :for carrying out an adjustment.

It is also an object of the present invention to provide :an adjustingdevice for spring loaded key levers which =-does not require atransmission, and consequently requires 1 fewer parts permitting a moreeconomical manufacture.

With these objects in view, the present invention mainly consists in adevice for adjusting the spring loading of key levers and comprises, incombination, supporting means, at least one key lever movably mounted onthe supporting :means, spring means connected at one end to the keylever means, and at the other end thereof to adjusting position foractuating the respective type.

means which are mounted on the supporting means for movement between aplurality of adjusted positions. The adjusting means hold the springmeans in each of the adjusted positions resiliently deformed tosubstantially the same extent, and angularly displace the spring meanswith respect to the key lever means during movement between the adjustedpositions. Consequently, the spring tension of the spring means remainssubstantially the same in all adjusted positions of the adjusting means,while a different component of the spring tension acts on the key levermeans in each of the adjusted positions. Suitable operating means areprovided for moving the adjusting means between the adjusted positionsthereof.

According to a preferred embodiment of the present invention, a set ofkey lever means is provided, which are simultaneously adjusted. Each keylever means includes an attaching hook means having a part-circular edgeengaged by one end of the respective spring so that the spring isturnable about the axis .of the part-circular edge. The attaching hookmeans are arranged in a row, and all springs associated with the keylevers are turnasble about a common axis. The adjusting means areturnable about an axis coinciding with the above-mentioned common axis,and include a transverse bar extending across all key levers, andsupporting the other ends of the springs. When the adjusting means areturned by suitable operating means, the springs are turned about thecommon axis, and consequently the relative angular positions betweeneach spring and the associated key lever is varied without infiuencingthe spring tension. However, due to the fact that only a component ofthe spring tension is eifective with respect to the key lever, amovement of the adjusting means between the adjusted positions willresult in differeut spring loading of the key levers. The novel featureswhich are considered as character istic for the invention are setforthin particular in the appended claims. The invention itself, however,both ,as to its construction and its method of operation, together withadditional objects and advantages thereof, will be best understood fromthe following description of specific ,embodiments when read inconnection with the accompanying drawings, in which;

Fig. 1 is a fragmentary side view, partly in section, illustrating apreferred embodiment of the present invention; and

Fig. 2 is a fragmentary plan view, partly in section, of the embodimentillustrated in Fig. 1.'

Referring now to the drawing, a set of key lever means 2 is pivotallymounted in the supporting means of the machine for pivotal movementabout the pivot means 3. Each key lever 2 is provided with a key 1, andis associated by means which are not shown in the drawing, with a typelever of an oflice machine, such as a typewriter, a calculator, or anaccounting machine. When the key lever means 1, 2 is depressed, it movesfrom the normal position illustrated in Fig. 1 to an actuated Each keylever means includes a hookshaped attaching means 20 having apart-circular edge 21. A set of spring means 4 is associated with theset of key levers 2, each spring 4 having at one end an engaging hook 5which engages the part-circular edge of the associated attaching hookmeans 2t} and is slidable along the same so that the end of the spring 4turns about the axis A of the part-circular edge 21. Since all centersof the part-circular edges 21 are aligned, the axis A is common to allsprings 4.

An adjusting means is provided for adjusting the positions of thesprings 4. The illustrated adjusting means includes a pair of arms 9which are connected by a transverse bar member 7. Each of the arms 9 ismounted in the supporting means of the machine for turning movementabout an axis coinciding with the axis A. In the Patented June 16, 1959illustrated embodiment, the supporting means include two walls 12, andthe arms 9 are turnable about pins 10 passing through bores 11 in thewalls 12 and being secured to the same by nuts llliz'cooperating withthreaded portions of the pivot pins 10.

The transverse bar member 7 which extends between the arms 9 across theset of key levers 2, has a set of perforations 6, each perforation 6being located opposite a key lever 2, one perforation 6 being associatedwith each spring 4 and each key lever 2. The other ends of the springs 4are hook-shaped and engage the associated perforations 6, so that thelength of the springs 4'is not changed when the adjusting means 7, 9 areturned about the axis A of the pivot pins 10. During such movement ofthe adjustingmeans 9, 7, the end portion 5 of each spring slides alongthe part-circular edge 21 ofthe respective hookshaped attaching means20' and performs a movement aboutthe same axis A. An operating means isprovided for turning the adjusting means 9, 7 about the pins 10, and isillustrated to be a handle lever 8 fixedly connected to a portion of theadjusting means located intermediate one arm 9 and the transverse bar 7.It will be appreciated that only the friction between the end portions 5and the edges 21, and the friction of the pins 10 has to be overcomewhen the adjusting means 9, 7 are turned through handle lever 8. Thehandle lever 8 may be operated in opposite directions out of theillustrated position and in directions of the arrows indicated by aminus sign.

In the illustrated position, each spring '4 urges the associated keylever means 1, '2 into engagement with the stationary stop 13. A certainpredetermined and selected spring tension is present in this position.When the key lever means 1, 2 is actuated, the key lever 2 moves awayfrom the stop 13, and the respective spring 4 is tensioned to a greaterdegree so that upon release of the key lever means 1, 2, the respectivespring 4 returns the key lever means from the actuated position to thenormal illustrated position engaging the stop 13.

The maximum spring tension is exerted in the illustrated position inwhich the spring 4 extends perpendicular to the key lever 2. When thekey lever means 1, 2 is actuated, the attaching means 20, and the end 5of the spring 4 moves in a direction substantially perpendicular to thekey lever 2 about the pivot pin 3. Consequently during'actuation ofthekey lever in the illustrated position of the adjusting means 9, 7 andof the springs 4, the full spring tension has to be overcome when thekey lever means is actuated.

However, when the adjusting means 9, 7 are turned by the operating means8 out of the position illustrated in solid lines and into the positionillustrated in broken lines in Fig. 1, only a component of the springtension P acts in the direction of movement of the attaching means 20.The spring tension of the respective spring 4 remains the same, sincethe distance between the ends of the respective spring 4 does not changewhen the adjusting means 7, 9 are'turned aboutthe axis A. The invariableconstant spring tension is indicated by a vector P. When the adjustingmeans are in the position illustratedin broken lines, only the force Pis etfectiveon the key lever means, and such force P is equal to P cosa, a beingthe ang'le through which the adjusting means 7, 9and thespring 'means 4 are turned.

Assuming a distance L between the axis of the pivot means 3 and the axisA, the maximal moment exerted by the respective'spring means 4 is P L.In the adjusted positions of the adjusting .means, the turning moment issmaller and equals P'XL whichis the same as'PXL sinceL is L cos a.

"From the above description of the preferred embodiment of the presentinvention it will become apparent that the spring forces acting on thekey levers can be adjusted by turning the adjusting meansjabout-the axisA. During such turning movement of the adjusting means, the springtension of the springs 4 is not varied at all so that only frictionalforces have to be overcome by operating the adjusting means.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofadjusting devices for spring loaded levers differing from the typesdescribed above.

While the invention has been illustrated and described as embodied in anadjusting device for a set of spring loaded key levers in which an equalspring tension is maintained in all adjusted positions of the devicewhile a different component of the spring tension acts on the key leversin each adjusted position, it ,is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of-the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range "of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A device for adjusting the spring loading of type actions comprising,in combination, supporting means; lever means mova'bly mounted on saidsupporting means; spring means connected at one end thereof to saidlever means for turning movement about an axis; adjusting means mountedon said supporting means for turning movement about said axis between aplurality of adjusted positions, said adjusting means being connected tothe other end of said spring means, and moving said other end of saidspring means along a circular path having its center in said axis forholding said spring means in each of said adjusted positions resilientlydeformed to the same extent, and for angularly displacing said springmeans with respect to said lever means so that the spring tension ofsaid spring means remains the same in all said adjusted positions ofsaid adjusting means, while a different component of said spring tensionacts on said lever means in each of said adjusted positions; andoperating means for moving said adjusting means between said adjustedpositions thereof.

2. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction duringmovement ofsaid key lever means from said normal position to said actuatedposition; spring means connected at one end thereofto said firstattaching means for turning movement about an axis; adjusting meansmounted on said supporting means for turning movement about'said axisbetween a plurality of, adjusted positions, said adjusting meansincluding second attaching means connected to the other end of saidspring means and being movable along a circular path about said firstattaching means while said key lever means is in said normal position,and moving said other end of said spring means along a circular pathhaving its center in said axis so that said spring means remainsresiliently deformed to the same extent and the spring tension of saidspring means remains the same in each of said adjusted positions, whilethe spring force acting on said key lever means is the component in.said one direction of said springtension of said spring means whereby ineach of said padjusted positions, .a different component-of said springtension acts on said key lever means; and operating means connected tosaid adjusting means for moving said adjusting means between saidadjusted positions thereof. 7

3. A device for adjusting the spring loading of type actions comprising,in combination, supporting means; lever means including a firstattaching means, said lever means being mounted on said supporting meansfor movement between a normal position and an actuated position, saidfirst attaching means moving in one direction during movement of saidlever means from said normal position to said actuated position; springmeans connected at one end thereof to said first attaching means forturning movement about an axis; adjusting means mounted on saidsupporting means for turning movement about said axis between aplurality of angularly displaced adjusted positions, said adjustingmeans including second attaching means connected to the other end ofsaid spring means and being movable along a circular path about saidfirst attaching means while said lever means is in said normal position,and moving said other end of said spring means along a circular pathhaving its center in said axis so that said spring means remainsresiliently deformed to the same extent and the spring tension of saidspring means remains the same in each of said adjusted positions, whilethe spring force acting on said lever means is the component in said onedirection of said spring tension of said spring means whereby in each ofsaid adjusted positions, a different component of said spring tensionacts on said lever means; and operating means connected to saidadjusting means for moving said adjusting means between said adjustedpositions thereof.

4. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid key lever means from said normal position to said actuatedposition; spring means connected at one end thereof to said firstattaching means for turning movement about an axis; adjusting meansmounted on said supporting means for turning movement about said axisbetween a plurality of adjusted positions, said adjusting meansincluding second attaching means connected to the other end of saidspring means and being movable along a circular path about said firstattaching means while said key lever means is in said normal position,and moving said other end of said spring means along a circular pathhaving its center in said axis so that said spring means remainsresiliently deformed to the same extent and the spring tension of saidspring means remains the same in each of said adjusted positions, whilethe spring force acting on said key lever means is the component in saidone direction of said spring tension of said spring means whereby ineach of said adjusted positions, a different component of said springtension acts on said key lever means, said spring means extending insaid one direction in one of said adjusted positions of said adjustingmeans; and handle means fixedly connected to said adjusting means forturning said adjusting means between said adjusted positions thereof.

5. A device for adjusting the spring loading of type actions comprising,in combination, supporting means; a set of lever means each including afirst attaching means, said lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid lever means from said normal position to said actuated position andbeing aligned along a straight line in said normal position; springmeans connected at one end thereof to each first attaching means formovement about an axis coinciding with said straight line; adjustingmeans mounted on said supporting means for turning movement about saidaxis between a plurality of adjusted positions, said adjusting meansincluding a set of second attaching means aligned along a straight lineparallel to said axis and connected to the other ends of said springmeans and being movable along a circular path about said axis while saidlever means is in said normal position, and moving said other end ofsaid spring means along a circular path having its center in said axisso that each spring means remains resiliently deformed to the sameextent and the spring tension of said spring means remains the same ineach of said adjusted positions, while the spring force acting on saidlever means is the component in said one direction of said springtension of said spring means whereby in each of said adjusted positions,a difierent component of said spring tension acts on said lever means;and operating means connected to said adjusting means for moving saidadjusting means between said adjusted positions thereof.

6. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid key lever means from said normal position to said actuatedposition; spring means connected at one end thereof to said firstattaching means for movement about an axis; adjusting means mounted onsaid supporting means for turning movement about said axis between aplurality of angularly displaced adjusted positions, said adjustingmeans including second attaching means connected to the other end ofsaid spring means and being movable along a circular path about saidaxis While said key lever means is in said normal position, and movingsaid other end of said spring means along a circular path having itscenter in said axis so that said spring means and the spring tension ofsaid spring means remains substantially the same in each of saidadjusted positions, while the spring force acting on said key levermeans is the component in said one direction of said spring tension ofsaid spring means whereby in each of 'said adjusted positions, adiiferent component of said spring tension acts on said key lever means,said spring means extending in said one direction in one of saidadjusted positions of said adjusting means; and operating meansconnected to said adjusting means for moving said adjusting meansbetween said adjusted positions thereof.

7. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including abook-shaped first attaching means, said key lever means being mounted onsaid supporting means for movement between a normal position and anactuated position, said first attaching means having a substantiallycincular edge and moving in one direction during movement of said keylever means from said normal position to said actuated position; springmeans connected at one end thereof to said first attaching means andslidably engaging said circular edge of the same so that said one end ofsaid spring means is movable along said circular edge about the axis ofsaid circular edge; adjusting means mounted on said supporting means forturning movement about said axis between a plurality of adjustedpositions, said adjusting means including second attaching meansconnected to the other end of said spring means and being movable alonga circular path about said axis of said circular edge of said firstattaching means while said key lever means is in said normal position,and

' moving said other end of said spring means along a circular pathhaving its center in said axis so that said spring means remainsresiliently deformed to substantially the same extent and the springtension of said spring means remains substantially the same in each ofsaid adjusted positions, while the spring force acting on said key levermeans is the component in said one direction of said spring tension ofsaid spring means whereby in each of said adjusted positions, adifferent component of said 7 spring tension acts on said key levermeans; and operating means connected to said adjusting means for movingsaid adjusting means between said adjusted positions thereof.

8. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid key lever means from said normal position to said actuatedposition; spring means connected at one end thereof to said firstattaching means for movement about an axis; adjusting means including atleast one arm turnably mounted on said supporting means for movementabout an axis coinciding with said axis between a plurality of angularlydisplaced adjusted positions, a transverse member extending transverseto said key lever means across the same and being fixedly connected tosaid arm, and second attaching means secured to said transverse memberopposite said key lever means, said second attaching means beingconnected to the other end of said spring means and movable along acircular path about said axis while said key lever means is in saidnormal position so that said spring means remains resiliently deformedto substantially the sameextent and the spring tension of said springmeans remains substantially the same in each of said adjusted positions,while the spring force acting on said key lever means is the componentin said one direction of said spring tension of said spring meanswhereby in each of said adjusted positions, a different component ofsaid spring tension acts on said key lever means; and operating meansconnected to said adjusting means for moving said adjusting meansbetween said adjusted positions thereof.

9. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid key lever means from said normal position to said actuatedposition; spring means connected at one end thereof to said firstattaching means for movement about an axis; adjusting means including atleast one arm turnably mounted on said supporting means for movementabout an axis coinciding with said axis between a plurality of angularlydisplaced adjusted positions, a transverse member extending transverseto said key lever means across the same and being fixedly connected tosaid arm, and second attaching means secured to said transverse memberopposite said key lever means, said second attaching means beingconnected to the other end of said spring means and movable along acircular path about said axis while said key lever means is in saidnormal position so that said spring means remains resiliently deformedto substantially the same extent and the spring tension of said springmeans remains substantially the same in each of said adjusted positions,while the spring force acting on said key lever means is the componentin said one direction of said spring tension of said spring meanswhereby in each of said adjusted positions, a different component ofsaid spring tension acts on said key lever means, said spring meansextending in said one direction in one of said adjusted positions ofsaid adjusting means; and operating means connected to said adjustingmeans for moving said adjusting means between said adjusted positionsthereof.

10. A device as set forth in claim 9 wherein said spring means extend insaid one adjusted position of said adjusting means perpendicular to saidkey lever means, and extend in the other adjusted positions of saidadjusting means at an acute angle to said key lever means.

11. A device for adjusting the spring loading of key levers comprising,in combination, supporting means; key lever means including a firstattaching means, said key lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means having a substantially circular edge andmoving in one direction during movement of said key lever means fromsaid normal position to said actuated position; spring means connectedat one end thereof to said first attaching means and engaging saidcircular edge of the same so that said one end of said spring means ismovable along said circular edge about the axis of said circular edge;adjusting means including at least one arm turnably mounted on saidsupporting means for movement about an axis coinciding with said axis ofsaid circular edge of said first attaching means for moving saidadjusting means between a plurality of adjusted positions, a transversemember extending transverse to said key lever means across the same andbeing fixedly connected to said arm, and second attaching means securedto said transverse member opposite said key lever means, said secondattaching means being connected to the other end of said spring meansand movable along a circular path about said axis of said circular edgewhile said key lever means is in said normal position so that saidspring means remains resiliently deformed to substantially the sameextent and the spring tension of said spring means remains substantiallythe same in each of said adjusted positions, while the spring forceacting on said key lever means is the component in said one direction ofsaid spring tension of said spring means whereby in each of saidadjusted positions, a ditferent component of said spring tension acts onsaid key lever means; and operating means connected to said adjustingmeans for moving said adjusting means between said adjusted positionsthereof.

12. A device as set forth in claim 11 wherein said spring means is anelongated coil spring means extending in one of said adjusted positionsof said adjusting means perpendicular to said key lever means, andextending in the other adjusted positions at an acute angle to said keylever means.

13. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching means movingin one direction during movement of the respective key lever means fromsaid normal position to said actuated position, said first attachingmeans being arranged in a row; a set of spring means, each spring meansconnected at one end thereof to one of said first attaching means formovement about a common axis extending parallel to said row; adjustingmeans including at least one arm turnably mounted on said supportingmeans for movement about an axis coinciding with said common axis formoving said adjusting means between a plurality of adjusted positions, atransverse bar fixedly connected to said arm and extending parallel tosaid common axis and to said row of attaching means across said set ofkey lever means, and a row of second attaching means secured to saidtransverse bar, each second attaching means being located opposite oneof said key lever means and being connected to the other end of therespective spring means associated with the respective key lever means,each of said second attaching means being movable along a circular pathabout said common axis while smd key lever means of said set of keylever means are in said normal positions so that each of said springmeans remains resiliently deformed to substantially the same extent, andthe spring tensions of said spring means are substantially equal in eachof said adjusted positions of said adjusting means while the springforces acting on said key lever means are the components in said onedirection of the spring tensions of said spring means .whereby in eachof said adjusted positions of said adjusting means dif ferent componentsof said equal spring tensions act on said key lever means of said set ofkey lever means; and an operating means secured to said adjusting meansfor moving said adjusting means between said adjusted positions thereof.

14. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching means movingin one direction during movement of the respective key lever means fromsaid normal position to said actuated position, said first attachingmeans being arranged in a row; a set of spring means, each spring meansconnected at one end thereof to one of said first attaching means formovement about a common axis extending parallel to said row; adjustingmeans including at least one arm turnably mounted on said supportingmeans for movement about an axis coinciding with said common axis formoving said said adjusting means between a plurality of adjustedpositions, a transverse bar fixedly connected to said arm and extendingparallel to said common axis and to said row of attaching means acrosssaid set of key lever means, and a row of second attaching means securedto said transverse bar, each second attaching means being locatedopposite one of said key lever means and being connected to the otherend of the respective spring means associated with the respective keylever means, each of said second attaching means being movable along acircular path about said common axis while said key lever means of saidset of key lever means are in said normal positions so that each of saidspring means remains resiliently deformed to substantially the sameextent, and the spring tensions of said spring means are substantiallyequal in each of said adjusted positions of said adjusting means whilethe spring forces acting on said key lever means are the components insaid one direction of the spring tensions of said spring means wherebyin each of said adjusted positions of said adjusting means diiferentcomponents of said equal spring tensions act on said key lever means ofsaid set of key lever means, said spring means extending in one of saidadjusted positions in said one direction and perpendicular to said keylever means; and an operating means secured to said adjusting means formoving said adjusting means between said adjusted positions thereof.

15. A device for simultaneously adjustin the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching means havinga circular edge and moving in one direction during movement of therespective key lever means from said normal position to said actuatedposition, said first attaching means being arranged in a row, and saidcircular edges having a common axis; a set of spring means, each springmeans connected at one end thereof to one of said first attaching means,each of said spring means engaging the circular edge of the respectivefirst attaching means so that said one end of each of said spring meansis movable along said circular edge about said common axis of saidcircular edges; adjusting means including at least one arm turnablymounted on said supporting means for movement about an axis coincidingwith said common axis for moving said adjusting means between aplurality of adjusted positions, a transverse bar fixedly connected tosaid arm and extending parallel to said common axis and to said row ofattaching means across said set of key lever means, and a row of secondattaching means secured to said transverse bar, each second attachingmeans being located opposite one of said key lever means and beingconnected to the other end of the respective spring means associatedwith the respective key lever means, each of said second attaching meansbeing movable along a circular path about said common axis while saidkey lever means of said set of key lever means are in said normalpositions so that each of said spring means remains resiliently deformedto substantially the same extent, and the spring tensions of said springmeans are substantially equal in each of said adjusted positions of saidadjusting means while the spring forces acting on said key lever meansare the components in said one direction of the spring tensions of saidspring means whereby in each of said adjusted positions of saidadjusting means different components of said equal spring tensions acton said key lever means of said set of key lever means; and an operatingmeans secured to said adjusting means for moving said adjusting means between said adjusted positions thereof.

16. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching hook meanshaving a partcircular edge and moving in one direction during movementof the respective key lever means from said normal position to saidactuated position, said first attaching hook means being arranged in arow and said part-circular edges having a common axis; a set of springmeans, each spring means connected at one end thereof to one of saidfirst hook attaching means, each of said spring means engaging thepart-circular edge of the respective first attaching means so that saidone end of each of said spring means is movable along said part-circularedge about said common axis of said circular edges; adjusting meansincluding at least one arm tur-nably mounted on said supporting meansfor movement about an axis coinciding with said common axis for movingsaid adjusting means between a plurality of adjusted positions, atransverse bar fixedly connected to said arm and extending parallel tosaid common axis and tosaid row of attaching means across said set ofkey lever means, and a row of second attaching means secured to saidtransverse bar, each second attaching means.

being located opposite one of said key lever means and being connectedto the other end of the respective spring means associated with therespective key lever means, each of said second attaching means beingmovable along a circular path about said common axis while said keylever means of said set of key lever means are in said normal positionsso that each of said spring means remains resiliently deformed tosubstantially the same extent, and the spring tensions of said springmeans are substantially equal in each of said adjusted positions of saidadjusting means while the spring forces acting on said key lever meansare the components in said one direction of the spring tensions of saidspring means whereby in each of said adjusted positions of saidadjusting means different components of said equal spring tensions acton said key lever means of said set of key lever means; and an operatingmeans secured to said adjusting means for moving said adjusting meansbetween said adjusted positions thereof.

17. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key 1 ver means including a first attaching means havinga circular edge and moving in one direction during movement of the'respective key lever means from said normal position to said actuatedposition, said first attaching means being arranged in a row, and saidcircular edges having a common axis; a set of coil spring means, eachspring means connected at one end thereof to one of said first attachingmeans, each of said spring means engaging the circular edge of therespective first attaching means so that said one end of each of saidspring means is movable along said circular edge about said common axisof said circular edges; adjusting means including at least one armturnably mounted on said supporting means for movement about an axiscoinciding with said common axis for moving said adjusting means betweena plurality of adjusted positions, a transverse bar fixedly connected tosaid arm and extending parallel to said common axis and to said row ofattaching means across said set of key lever means, and a row of secondattaching means secured to said transverse bar, each second attachingmeans being located opposite one of said key lever means and beingconnected to the other end of the respective coil spring meansassociated with the respective key lever means, each of said secondattaching means being movable along a circular path about said commonaxis while said key lever means of said set of key lever means are insaid normal positions so that each of said coil spring means remainsresiliently deformed to substantially the same extent, and the springtensions of said coil spring means are substantially equal in each ofsaid adjusted positions of said adjusting means while the spring forcesacting on said key lever means are the components in said one directionof the spring tensions of said coil spring means whereby in each of saidadjusted positions of said adjusting means difierent components of saidequal spring tensions act on said key lever means of said set of keylever means; and an operating means secured to said adjusting means formoving said adjusting means between said adjusted posi-' tions thereof.

18. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching means movingin one direction during movement of the respective key lever means fromsaid normal position to said actuated position, said first attachingmeans being arranged in a row; a set of spring means, each spring meansconnected at one end thereof to one of said first attaching mews formovement about a common axis extending parallel to said row; adjustingmeans including a pair of arms spaced in direction of said common axisand being turnably mounted on said supporting means for movement aboutan axis coinciding with said common axis for moving said adjusting meansbetween a plurality of adjusted positions, a transverse bar fixedlyconnected to and extending between said arms parallel to said commonaxis and to said row of attaching means across said set of key levermeans, and a row of second attaching means secured to said transversebar, each second attaching means being located opposite one of said keylever means and being connected to the other end of the respectivespring means associated with the respective key lever means, each ofsaid second attaching means being movable along a circular path aboutsaid common axis while said key lever means of said set of key levermeans are in said normal positions so that each of said spring meansremains resiliently deformed to substantially the same extent, and thespring tensions of said spring means aretsubstantially equal in each ofsaid adjusted positions of said adjusting means while the spring forcesacting on said key lever means are the components in said one directionof the spring tensions of said spring means whereby in each of saidadjusted positions of said adjusting means difierent components of saidequal spring tensions act on said key lever means of said set of keylever means; and an operating means secured to said adjusting means formoving said adjusting means between said adjusted positions thereof.

19. A device for simultaneously adjusting the spring loading of a set ofkey lever means, comprising, in combination, a set of parallel key levermeans, each key lever means being mounted on said supporting means forindependent pivotal movement between a normal position and an actuatedposition, each key lever means including a first attaching hook meanshaving a partcircular edge and moving in one direction during movementof the respective key lever means from said normal position to saidactuated position, said first attaching hook means being arranged in arow, and said partcircular edges having a common axis; a set of coilspring means, each spring means connected at one end thereof to one ofsaid first hook attaching means, each of said spring means engaging thepart-circular edge of the respective first attaching means so that saidone end of each of said spring means is movable along said partcircularedge about said common axis of said circular edges; adjusting meansincluding a pair of arms spaced in direction of said common axis andbeing turnably mounted on said supporting means for movement about anaxis coinciding with said common axis for moving said adjusting meansbetween a plurality of adjusted positions, a transverse bar fixedlyconnected to and extending between said arms parallel to said commonaxis and to said row of attaching means across said set of key levermeans, and a row of second attaching means secured to said transversebar, each second attaching means being located opposite one of said keylever means and being connected to the other end of the respective coilspring means associated with the respective key lever means, each ofsaid second attaching means being movable along a circular path aboutsaid common axis while said key lever means of said set of key levermeans are in said normal positions so that each of said coil springmeans remains resiliently deformed to substantially the same extent, andthe spring tensions of said coil spring means are substantially equal ineach of said adjusted positions of said adjusting means while the springforces acting on said key lever means are the components in said onedirection of the spring tensions of said coil spring means whereby ineach of said adjusted positions of said adjusting means differentcomponents of said equal spring tensions act on said key lever means ofsaid set of key lever means; and an operating means secured to saidadjusting means for moving said adjusting means between said adjustedpositions thereof.

20. A device for adjusting the spring loading of type actionscomprising, in combination, supporting means; lever means including afirst attaching means, said lever means being mounted on said supportingmeans for movement between a normal position and an actuated position,said first attaching means moving in one direction during movement ofsaid lever means from said normal position to said actuated position;spring means connected at one end thereof to said first attaching meansfor movement about an axis; adjusting means including at least one armturnably mounted on said supporting means for movement about an axiscoinciding with said axis between a plurality of angularly displacedadjusted positions, a transverse member extending transverse to saidlever means across the same and being fixedly connected to said arm, andsecond attaching means secured to said transverse member opposite saidlever means, said second attaching means being connected to the otherend of said spring means and movable along a circular path about saidaxis while said lever means is in said normal position so that saidspring means remains resiliently deformed to substantially the sameextent and the spring tension of said spring means remains substantiallythe means for moving said adjusting means between said same in each ofsaid adjusted positions, while the spring adjusted positions thereof.force acting on said lever means is the component in said one directionof said spring tension of said spring means References Clted 111 thefile 0f fllls Patent whereby in each of said adjusted positions, adifierent 5 UNITED STATES PATENTS component of said spring tension actson said lever means; and operating means connected to said adjusting2148877 Rauscher 1939

